The Seat,valve, cataloged under National Stock Number 4820-01-259-0505, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 17 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-259-0505 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.117 INCHES MINIMUM AND 0.127 INCHES MAXIMUM IN |
| Flange Diameter | 0.932 INCHES MINIMUM AND 0.942 INCHES MAXIMUM IN |
| Thread Length | 0.344 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Seal Accommodation Type | GROOVED |
| Criticality Code Justification | ZZZY |
| Style Designator | THREADED FLANGED |
| Material Document and Classification | QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Body Inside Diameter | 0.511 INCHES MINIMUM AND 0.521 INCHES MAXIMUM IN |
| Nominal Thread Size | 0.766 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 0.311 INCHES MINIMUM AND 0.321 INCHES MAXIMUM IN |
| Thread Class | 3A SINGLE THREADED PORTION A |
| Thread Quantity Per Inch | 24 SINGLE THREADED PORTION |
| Material | NICKEL ALLOY OVERALL |
| Seat Angle in Deg | 45.000 NOMINAL |
| Thread Series Designator | UNS SINGLE THREADED PORTION |
| Reference Number Differentiating Characteristics | MATERIAL WILL BE IN ACCORDANCE WITH SHIPS PARTS CONTROL CENTER ACTIVITY HX QUALITY CONTROL,MANUFACTURING AND TESTING SPECIFICATIONS |
| Seating Surface Shape | ANGULAR |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL F — Mutilate — Cut |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | C |
| Reference | Meaning |
|---|---|
| 2620-902X6PC4,0.500IN | 5/1 Secondary reference U.S. Government activity |
| 845-2445100 PC. 12 | 3/1 Design control — primary reference U.S. Government activity |
| 845-2445100PC12,0.500IN | 5/1 Secondary reference U.S. Government activity |
| 2632-903X1PC12,0.500IN | 5/1 Secondary reference U.S. Government activity |
NSN 4820-01-259-0505 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-259-0505: Flange Seat to Disk End Height: 0.117 INCHES MINIMUM AND 0.127 INCHES MAXIMUM IN; Flange Diameter: 0.932 INCHES MINIMUM AND 0.942 INCHES MAXIMUM IN; Thread Length: 0.344 INCHES NOMINAL SINGLE THREADED PORTION IN; Seal Accommodation Type: GROOVED. 17 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 4820-01-259-0505 has DEMIL Code F. Demilitarization may be required before disposal or transfer to non-military entities.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.